For four days I have been fighting joint pain, headaches with pressure behind the eyes, little to no appetite, no energy, and a dry cough, and some diarrhea, and vomiting.
I am a 46 year old male in decent shape, and not currently on any medications, besides Advil, and otc migraine medication.

With symptoms like that, I suggest you see a doctor. We do not diagnose on the internet, for obvious reasons.